[PATCH AUTOSEL 6.11 072/244] cpufreq: amd-pstate: add check for cpufreq_cpu_get's return value

Sasha Levin
2024-09-25T11:39:33Z

From: Anastasia Belova <abelova@astralinux.ru>

[ Upstream commit 5493f9714e4cdaf0ee7cec15899a231400cb1a9f ]

cpufreq_cpu_get may return NULL. To avoid NULL-dereference check it
and return in case of error.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Anastasia Belova <abelova@astralinux.ru>
Reviewed-by: Perry Yuan <perry.yuan@amd.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/cpufreq/amd-pstate.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 259a917da75f3..103b43e529b5f 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -656,7 +656,12 @@ static void amd_pstate_adjust_perf(unsigned int cpu,
unsigned long max_perf, min_perf, des_perf,
cap_perf, lowest_nonlinear_perf;
struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
- struct amd_cpudata *cpudata = policy->driver_data;
+ struct amd_cpudata *cpudata;
+
+ if (!policy)
+ return;
+
+ cpudata = policy->driver_data;

if (policy->min != cpudata->min_limit_freq || policy->max != cpudata->max_limit_freq)
amd_pstate_update_min_max_limit(policy);
@@ -870,11 +875,16 @@ static void amd_pstate_init_prefcore(struct amd_cpudata *cpudata)
static void amd_pstate_update_limits(unsigned int cpu)
{
struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
- struct amd_cpudata *cpudata = policy->driver_data;
+ struct amd_cpudata *cpudata;
u32 prev_high = 0, cur_high = 0;
int ret;
bool highest_perf_changed = false;

+ if (!policy)
+ return;
+
+ cpudata = policy->driver_data;
+
mutex_lock(&amd_pstate_driver_lock);
if ((!amd_pstate_prefcore) || (!cpudata->hw_prefcore))
goto free_cpufreq_put;
--
2.43.0